Returning home yesterday, satnav said I had 12 miles more to go than bike said I had fuel for. As I've started to carry extra fuel in a can, I thought I'd try pushing my luck. I didn't spare the throttle on the mostly fast country lanes and I still got to the petrol station 12.5 miles after bike said I had no fuel range left; bike ran fine during that time. I filled up with 11.7 litres of petrol and by my calculation from MPG figures, my extra 12 miles used 0.8 litres, so 'no fuel range' indication came on after 11 litres used. My Bonneville Speedmaster has a quoted tank capacity of 12 litres, though I don't know if that's meant to be 'usable' capacity, or actual capacity. I suspect latter, in which case the fuel pump would have been slurping the last dregs.

Thought I'd mention this here as I expect the fuel system and gauges in a lot of the modern Triumphs is the same and my experiment may be useful to other people.

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Returning home yesterday, satnav said I had 12 miles more to go than bike said I had fuel for. As I've started to carry extra fuel in a can, I thought I'd try pushing my luck. I didn't spare the throttle on the mostly fast country lanes and I still got to the petrol station 12.5 miles after bike said I had no fuel range left; bike ran fine during that time. I filled up with 11.7 litres of petrol and by my calculation from MPG figures, my extra 12 miles used 0.8 litres, so 'no fuel range' indication came on after 11 litres used. My Bonneville Speedmaster has a quoted tank capacity of 12 litres, though I don't know if that's meant to be 'usable' capacity, or actual capacity. I suspect latter, in which case the fuel pump would have been slurping the last dregs.

Thought I'd mention this here as I expect the fuel system and gauges in a lot of the modern Triumphs is the same and my experiment may be useful to other people.

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I have no idea if it's intentional, but I'm guessing that the manufacturers err on the side of caution. I'd rather have a bit left when it says empty, than be empty when it says I've got a bit left!

I also think that the fuel gauge is only intended as a guide and they are not that accurate.

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I was surprised that my bike's idea of distance was so accurate. After a recent 100 mile or so ride when I tested this, the trip meter and my satnav only disagreed by 0.1 mile.

From day one, I already knew speedo was spot on compared to satnav and roadside speed displays you see. That took some getting use to, as I'm use to them reading about 10% over, a difference that's important when there's speed cameras about!

I think the bike's idea of MPG is pretty good too, on next run I'll do some experiments to check fuel usage accuracy,